Devices including a near field transducer and at least one associated adhesion layer

ABSTRACT

Devices that include a near field transducer (NFT), the NFT having a disc and a peg, and the peg having five surfaces thereof; and at least one adhesion layer positioned on at least one of the five surfaces of the peg, the adhesion layer including one or more of the following: yttrium (Y), tin (Sn), iron (Fe), copper (Cu), carbon (C), holmium (Ho), gallium (Ga), silver (Ag), ytterbium (Yb), chromium (Cr), tantalum (Ta), iridium (Ir), zirconium (Zr), yttrium (Y), scandium (Sc), cobalt (Co), silicon (Si), nickel (Ni), molybdenum (Mo), niobium (Nb), palladium (Pd), titanium (Ti), rhenium (Re), osmium (Os), platinum (Pt), aluminum (Al), ruthenium (Ru), rhodium (Rh), vanadium (V), germanium (Ge), tin (Sn), magnesium (Mg), iron (Fe), copper (Cu), tungsten (W), hafnium (Hf), carbon (C), boron (B), holmium (Ho), antimony (Sb), gallium (Ga), manganese (Mn), silver (Ag), indium (In), bismuth (Bi), zinc (Zn), ytterbium (Yb), and combinations thereof.

PRIORITY

This application claims priority to U.S. Provisional Application No.62/002,882, entitled NEAR FIELD TRANSDUCERS WITH ADHESION LAYERS ANDMETHODS, filed on May 25, 2014, and Ser. No. 62/078,098 entitled NEARFIELD TRANSDUCERS WITH ADHESION LAYERS AND METHODS, filed on Nov. 11,2014, the disclosures of which are incorporated herein by referencethereto.

SUMMARY

Disclosed are devices that include a near field transducer (NFT), theNFT having a disc and a peg, and the peg having five surfaces thereof;and at least one adhesion layer positioned on at least one of the fivesurfaces of the peg, the adhesion layer including one or more of thefollowing: yttrium (Y), tin (Sn), iron (Fe), copper (Cu), carbon (C),holmium (Ho), gallium (Ga), silver (Ag), ytterbium (Yb), or combinationsthereof combinations thereof. and combinations thereof.

Also disclosed are devices that include an energy source; a near fieldtransducer (NFT) configured to receive energy from the energy source,the NFT having a disc and a peg, and the peg having five surfacesthereof; and at least one adhesion layer positioned on at least one ofthe five surfaces of the peg, the adhesion layer including one or moreof the following: and combinations thereof.

Also disclosed are devices that include an energy source; a near fieldtransducer (NFT) configured to receive energy from the energy source,the NFT having a disc and a peg, and the peg having five surfacesthereof; and at least one adhesion layer positioned on at least one ofthe five surfaces of the peg, the adhesion layer having a thickness fromabout 10 Å to about 35 Å, and the adhesion layer including one or moreof the following: chromium (Cr), tantalum (Ta), iridium (Ir), zirconium(Zr), yttrium (Y), scandium (Sc), cobalt (Co), silicon (Si), nickel(Ni), molybdenum (Mo), niobium (Nb), palladium (Pd), titanium (Ti),rhenium (Re), osmium (Os), platinum (Pt), aluminum (Al), ruthenium (Ru),rhodium (Rh), vanadium (V), germanium (Ge), tin (Sn), magnesium (Mg),iron (Fe), copper (Cu), tungsten (W), hafnium (Hf), carbon (C), boron(B), holmium (Ho), antimony (Sb), gallium (Ga), manganese (Mn), silver(Ag), indium (In), bismuth (Bi), zinc (Zn), ytterbium (Yb), orcombinations thereof.

Also disclosed are near field transducers (NFT), the NFTs having a discand a peg, and the peg having five surfaces thereof and a region thatextends into the disc; and at least one adhesion layer positioned on atleast four surfaces of the five surfaces of the peg, the adhesion layerincluding one or more of the following: yttrium (Y), tin (Sn), iron(Fe), copper (Cu), carbon (C), holmium (Ho), gallium (Ga), silver (Ag),ytterbium (Yb), or combinations thereof combinations thereof.

Also disclosed are methods forming a structure, the structure includinga bottom adhesion layer; a peg and disc structure on the bottom adhesionlayer, the peg and disc structure having both top surfaces and sidesurfaces; a second adhesion layer on the top and side surfaces of thepeg and disc structure; a capping layer on the second adhesion layer;and an amorphous carbon layer on the capping layer; and removing atleast a portion of the second adhesion layer via vertical ion millingand chemical mechanical polishing wherein the amorphous carbon layerfunctions as a stop layer for the second adhesion layer.

The above summary of the present disclosure is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which examples can beused in various combinations. In each instance, the recited list servesonly as a representative group and should not be interpreted as anexclusive list.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a magnetic disc drive that can includeHAMR devices.

FIG. 2 is a cross sectional view of a perpendicular HAMR magneticrecording head and of an associated recording medium.

FIGS. 3A, 3B, and 3C are perspective views of an illustrative NFT (FIG.3A) and the peg thereof (FIG. 3B), and a cross sectional view of (FIG.3C) of the NFT and surrounding structures.

FIG. 4 shows a cross section of an illustrative portion of a structurethat includes a disclosed adhesion layer.

FIGS. 5A through 5D depict an illustrative process sequence to form adevice that includes disclosed adhesion layer.

FIGS. 6A through 6D depict an illustrative process sequence to form adevice that includes disclosed adhesion layer.

FIGS. 7A through 7G depict an illustrative process sequence to form adevice that includes disclosed adhesion layer.

FIGS. 8A through 8F depict an illustrative process sequence to form adevice that includes disclosed adhesion layer.

The figures are not necessarily to scale. Like numbers used in thefigures refer to like components. However, it will be understood thatthe use of a number to refer to a component in a given figure is notintended to limit the component in another figure labeled with the samenumber.

DETAILED DESCRIPTION

Heat assisted magnetic recording (referred to through as HAMR) utilizesradiation, for example from a laser, to heat media to a temperatureabove its curie temperature, enabling magnetic recording. In order todeliver the radiation, e.g., a laser beam, to a small area (on the orderof 20 to 50 nm for example) of the medium, a NFT is utilized. During amagnetic recording operation, the NFT absorbs energy from a laser andfocuses it to a very small area; this can cause the temperature of theNFT to increase. The temperature of the NFT can be elevated up to about400° C. or more. The very high temperatures that are reached duringoperation can often lead to failure of the NFT and associate magneticrecording head.

A possible contributing factor to the failure of the NFT may be poormechanical robustness and thermal stability of the NFT material, e.g.,gold (Au). Gold has low hardness, grows grains easily and exhibitsplastic reflow. One way to improve the mechanical robustness of gold(and other plasmonic material) is through doping. By adding anotherelement into the Au, either embedded within grains or residing on Augrain boundaries, Au grains can be refined and stabilized. However suchmodifications to the plasmonic material will usually degrade the opticalproperties and thermal conductivity of Au. Thus a balance betweenimproving mechanical strength and maintaining other physical and opticalproperties at acceptable levels is needed. As a result, the optimizeddoping level is typically very low, e.g. <1 at %. Such ultra-low dopinglevels can be realized either through co-sputtering from two targets orthrough sputtering from a single alloy target. Co-sputtering is not apreferred manufacturing approach due to the complexity in controllingthe process. Also, such processes are limited by the mixing ratiobetween different elements due to the constraints on sputter powerselection. In the single alloy target approach, the challenge lies inobtaining targets that produce repeatable doping levels, both within atarget and from target to target. Therefore, there is a need to have areliable and practically manufacturable way to realize ultra-low dopingin films such as gold, if ultralow doping is to be utilized.

Another aspect of NFT failure is believed to be related to theinterfacial characteristics at the NFT/cladding interface (e.g.,Au/oxide interface). In current HAMR NFT designs, an Au NFT, forexample, is surrounded by oxide cladding materials, e.g. SiO₂ or AlO forcore-NFT spacer (CNS) and NFT-pole spacer (NPS). An Au/oxide interfaceis known to be a relatively weak interface. While Au has a highersurface energy (1.5 J/m²), the typical optical cladding oxides used inHAMR have with much lower values, e.g. 0.2 J/m² for SiO₂ and 0.9 J/m²for AlO. Such a low surface energy, as well as a high interfacial energybetween Au and the oxide, makes it energetically favorable for Au todetach from the surrounding oxides, which could lead to interfacialdiffusion and peg deformation. Thus lowering the interfacial energybetween Au and oxides may improve NFT stability.

Disclosed devices include one or more layers adjacent one or moresurfaces of the peg of the NFT to increase or improve adhesion of thepeg material to the surrounding materials or structures within thedevice. If the peg is better adhered to the surrounding materials orstructures, it will be less likely to deform and/or recess, andmaterials from such an adhesion layer could also be designed to diffuseinto the peg in order to dope the material of the peg.

FIG. 1 is a perspective view of disc drive 10 including an actuationsystem for positioning slider 12 over track 14 of magnetic medium 16.The particular configuration of disc drive 10 is shown for ease ofdescription and is not intended to limit the scope of the presentdisclosure in any way. Disc drive 10 includes voice coil motor 18arranged to rotate actuator arm 20 on a spindle around axis 22. Loadbeam 24 is connected to actuator arm 20 at head mounting block 26.Suspension 28 is connected to an end of load beam 24 and slider 12 isattached to suspension 28. Magnetic medium 16 rotates around an axis 30,so that the windage is encountered by slider 12 to keep it aloft a smalldistance above the surface of magnetic medium 16. Each track 14 ofmagnetic medium 16 is formatted with an array of data storage cells forstoring data. Slider 12 carries a magnetic device or transducer (notshown in FIG. 1) for reading and/or writing data on tracks 14 ofmagnetic medium 16. The magnetic transducer utilizes additionalelectromagnetic energy to heat the surface of medium 16 to facilitaterecording by a process termed heat assisted magnetic recording (HAMR).

A HAMR transducer includes a magnetic writer for generating a magneticfield to write to a magnetic medium (e.g. magnetic medium 16) and anoptical device to heat a portion of the magnetic medium proximate to thewrite field. FIG. 2 is a cross sectional view of a portion of a magneticdevice, for example a HAMR magnetic device 40 and a portion ofassociated magnetic storage medium 42. HAMR magnetic device 40 includeswrite pole 44 and return pole 46 coupled by pedestal 48. Coil 50comprising conductors 52 and 54 encircles the pedestal and is supportedby an insulator 56. As shown, magnetic storage medium 42 is aperpendicular magnetic medium comprising magnetically hard storage layer62 and soft magnetic underlayer 64 but can be other forms of media, suchas patterned media. A current in the coil induces a magnetic field inthe pedestal and the poles. Magnetic flux 58 exits the recording head atair bearing surface (ABS) 60 and is used to change the magnetization ofportions of magnetically hard layer 62 of storage medium 42 enclosedwithin region 58. Near field transducer 66 is positioned adjacent thewrite pole 44 proximate air bearing surface 60. Near field transducer 66is coupled to waveguide 68 that receives an electromagnetic wave from anenergy source such as a laser. An electric field at the end of nearfield transducer 66 is used to heat a portion 69 of magnetically hardlayer 62 to lower the coercivity so that the magnetic field from thewrite pole can affect the magnetization of the storage medium.

Devices disclosed herein can also include other structures. Devicesdisclosed herein can be incorporated into larger devices. For example,sliders can include devices as disclosed herein. Exemplary sliders caninclude a slider body that has a leading edge, a trailing edge, and anair bearing surface. The write pole, read pole, optical near fieldtransducer and contact pad (and optional heat sink) can then be locatedon (or in) the slider body. Such exemplary sliders can be attached to asuspension which can be incorporated into a disc drive for example. Itshould also be noted that disclosed devices can be utilized in systemsother than disc drives such as that depicted in FIG. 1.

FIGS. 3A and 3B show an example of the peg and disc of a peg and disctype NFT, and FIG. 3B shows a closer view of only the peg of the peg anddisc type NFT shown in FIG. 3A. The NFT in FIG. 3A includes a peg 305and a disc 310. In some embodiments, the disc 310 can also include aportion that functions as a heat sink. In such embodiments, a bottomportion of the disc having substantially the same thickness as the pegcan be considered the disc and the portion above that can be consideredthe heat sink. In some embodiments, the disc and the heat sink can be asingle structure that was formed in the same step (or steps), and insome embodiments, the disc and heat sink can be formed separately (butof the same or a different material). The peg 305 shown in FIGS. 3A and3B includes five surfaces that are not in contact with the disc 310, anair bearing surface 306, a first surface 307, a second surface 309, athird surface 308, and a fourth surface 311.

In some embodiments, the second surface 309 and the first surface 307are facing the pole and core respectively. In some embodiments, thethird surface 308 and the fourth surface 311 are not facing the pole orthe core. More specifically, the third surface 308 would be located infront of the paper on which FIG. 2 is depicted and the fourth surface311 would be located behind the paper on which FIG. 2 is depicted. Insome embodiments, the second surface 309 can also be referred to as theNFT-pole surface which faces a NFT-pole space, which can be referred toas a NPS (not shown herein). In some embodiments, the first surface 307can also be referred to as the NFT-core surface, which faces a NFT-corespace, which can be referred to as CNS (not shown herein). In someembodiments, the third surface 308 can also be described as the surfacewhich faces the left side of a device, in some embodiments; a left solidimmersion mirror can be located there. In some embodiments, the fourthsurface 311 can also be described as the surface which faces the rightside of a device, in some embodiments; a right solid immersion mirrorcan be located there.

FIG. 3C shows a cross section of a device taken perpendicular to the airbearing surface (ABS). The device includes a write pole 340, a waveguidecore 320, optical cladding 350 and a NFT 330. The portion of thecladding between the core 320 and the NFT 330 is depicted by numeral 336and can be referred to as the core to NFT space, or CNS. The portion ofthe cladding between the pole 340 and the NFT 330 is depicted by numeral337 and can be referred to as the pole to NFT space, or NPS. Between theNFT 330 and the optical cladding 350 is an illustrative adhesion layer335. The embodiment depicted in FIG. 3C shows the adhesion layer 335located around portions of the peg 331 and the disc 332. The adhesionlayer 335 in FIG. 3C may be considered substantially the same as if itwere on the first surface 307 of FIG. 3B. Similarly, the adhesion layer337 in FIG. 3C may be considered substantially the same as if it were onat least the second surface 309 of the peg as well as on some portion ofthe surface of the disc 310 that faces the peg 305 (see FIG. 3A). Theadhesion layer 337 in FIG. 3C may also be present on the third surface308 and the fourth surface 311 (of FIG. 3B), but the particular crosssection in FIG. 3C makes it impossible to know. In some embodiments, theadhesion layer 335 can be located on different surfaces of the NFT 330than that shown in the cross section of FIG. 3C. One of skill in theart, having read this specification will understand that NFT types otherthan peg and disk (also referred to as “lollipop” type NFTs) could beutilized herein. For example plasmonic gap type NFTs and peg only NFTscan also be utilized.

Disclosed devices can include one or more adhesion layers located on oneor more surfaces of a NFT. In some embodiments, disclosed devices caninclude one or more adhesion layers located on one or more surfaces of apeg of a NFT. In some embodiments, disclosed devices can includeadhesion layers located on two or more surfaces of a peg of a NFT. Insome embodiments, disclosed devices can include adhesion layers locatedon three or more surfaces of a peg of a NFT. In some embodiments,disclosed devices can include adhesion layers located on four or moresurfaces of a peg of a NFT. In some embodiments, disclosed devices caninclude adhesion layers located on all five surfaces of a peg of a NFT.In some embodiments disclosed devices can include adhesion layerslocated on each of the first surface 307, the second surface 309, thethird surface 308, and the fourth surface 311. Adhesion layers ondifferent surfaces of the peg could have different materials. In someembodiments, the adhesion layer on one or more surfaces could bedifferent in order to reduce the optical penalty.

The material of the adhesion layer can be selected based, at least inpart on some of the following properties: good wettability on the NFTsurface (e.g., a Au containing surface, in some more specificillustrative embodiments, a Au (111) surface); intermediate solubilitywith the NFT material and in some specific embodiments a negative heatof mixing with the NFT material; a relatively small mismatch (in someembodiments a negligible mismatch) between the layers of the adhesionlayer material (e.g., metal layer) and the NFT material (e.g., Au, ormore specifically in some embodiments Au (111)); a free energy of oxideformation of the material that is similar to or slightly less than theoxide of the cladding material; a high melting point; chemically stablewith the NFT material without forming intermetallic materials;self-passivation with oxygen; or combinations thereof.

Disclosed structures or layers can be generally described, irrespectiveof the larger structure they exist in, the shape and form of thestructures or layers, or combinations thereof, by a stack structure. Anexample of such a stack structure is shown in FIG. 4. The structure inFIG. 4 shows the NFT 430, the NFT to pole space (NPS) 410, the core toNFT space (CNS) 450, an optional seed layer 440 and a disclosed adhesionlayer 420. As seen in this illustration, the adhesion layer 420 ispositioned between the NPS 410 which is a cladding material and the NFT430.

As discussed above, both the NPS 410 and the CNS 450 generally includeoxide materials. In some embodiments, the cladding material can includealuminum oxide (AlO), silicon oxide (SiO₂), yttrium oxide (Y₂O₃),magnesium fluoride (MgF₂), or combinations thereof for example. In someembodiments, the cladding layers, e.g., the NPS, the CNS, or both mayhave a thickness that is about 25 nanometers (nm). The optional seedlayer can generally have a thickness that is not less than 5 Å but notgreater than 10 Å. In some embodiments, the optional seed layer caninclude materials that may or may not be the same as those of theadhesion layer. In some embodiments, an optional seed layer that has thesame materials as the adhesion layer, same thickness as the adhesionlayer, or any combination thereof may be utilized. In some embodiments,an optional seed layer that has different materials than the adhesionlayer, different thicknesses than the adhesion layer, or any combinationthereof may be utilized.

The NFT 430 can include plasmonic materials. In some embodiments,various materials including, for example, gold (Au), silver (Ag), copper(Cu), alloys thereof, or other materials can be utilized to form a NFT.In some embodiments, the NFT can also be made of materials listed inU.S. Patent Publication No. 2013/0286799, U.S. Pat. No. 8,427,925, andU.S. patent application Ser. No. 13/923,925 entitled MAGNETIC DEVICESINCLUDING FILM STRUCTURES, filed on Jun. 21, 2013, and Ser. No.14/062,651 entitled RECORDING HEADS INCLUDING NFT AND HEATSINK, filed onOct. 24, 2013, the disclosures of which are incorporated herein byreference thereto.

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more metals. Insome embodiments, the metal can include specific illustrative metalssuch as for example yttrium (Y), tin (Sn), iron (Fe), copper (Cu),carbon (C), holmium (Ho), gallium (Ga), silver (Ag), ytterbium (Yb), orcombinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Sn, Fe, Cu, Ga, Ag, orcombinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Ho, Yb, or combinationsthereof. In some embodiments, the metal can include specificillustrative metals such as for example Y. In some embodiments, themetal can include specific illustrative metals such as for example C.

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more metals. Insome embodiments, the metal can include specific illustrative metalssuch as for example chromium (Cr), tantalum (Ta), iridium (Ir),zirconium (Zr), yttrium (Y), scandium (Sc), cobalt (Co), silicon (Si),nickel (Ni), molybdenum (Mo), niobium (Nb), palladium (Pd), titanium(Ti), rhenium (Re), osmium (Os), platinum (Pt), aluminum (Al), ruthenium(Ru), rhodium (Rh), vanadium (V), germanium (Ge), tin (Sn), magnesium(Mg), iron (Fe), copper (Cu), tungsten (W), hafnium (Hf), carbon (C),boron (B), holmium (Ho), antimony (Sb), gallium (Ga), manganese (Mn),silver (Ag), indium (In), bismuth (Bi), zinc (Zn), ytterbium (Yb), orcombinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Sc, Ti, V, Cr, Mn, Fe,Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Pt,Ir, or combinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example B, Al, Ga, In, orcombinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example C, Si, Ge, Sn, orcombinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Sb, Bi, or combinationsthereof. In some embodiments, the metal can include specificillustrative metals such as for example Ho, Yb, or combinations thereof.In some embodiments, an adhesion layer can include alloys of the notedelements, including for example NiFe and TiW. It should also be notedthat adhesion layers can include alloys that include one of the notedelements and an element not specifically called out herein.

Disclosed adhesion layers can have various thicknesses. The thickness ofan adhesion layer can refer to the average thickness of the adhesionlayer. In some embodiments, a disclosed adhesion layer can have athickness that is at least 1 Å, in some embodiments at least 2 Å, or insome embodiments at least 10 Å. In some embodiments, a disclosedadhesion layer can have a thickness that is not greater than 60 Å, notgreater than 50 Å, not greater than 35 Å, or even not greater than 30 Å.The thickness (e.g., the average thickness) of an adhesion layer can bemeasured using, for example, transmission electron microscopy (TEM),X-ray reflectivity (XRR), or x-ray photoelectron spectroscopy (XPS). Thethickness can be determined using calibration from standard sampleshaving known thicknesses, for example.

One of skill in the art, having read this specification will understandthat NFT types other than peg and disk (also referred to as “lollipop”type NFTs) could be utilized herein. For example plasmonic gap type NFTsand peg only NFTs can also be utilized. In some embodiments, variousmaterials including, for example, gold (Au), silver (Ag), copper (Cu),alloys thereof, or other materials can be utilized to form a NFT. Insome embodiments, the NFT can also be made of materials listed in U.S.Patent Publication No. 2013/0286799, U.S. Pat. No. 8,427,925, and U.S.patent application Ser. No. 13/923,925 entitled MAGNETIC DEVICESINCLUDING FILM STRUCTURES, filed on Jun. 21, 2013, and Ser. No.14/062,651 entitled RECORDING HEADS INCLUDING NFT AND HEATSINK, filed onOct. 24, 2013, the disclosures of which are incorporated herein byreference thereto.

In some embodiments, materials that can be utilized for adhesion layerscan be those that provide acceptable levels of NFT coupling efficiencyloss. Such materials can generally have relatively high indices ofrefraction (n). The presence of a non-plasmonic material layer, e.g., adisclosed adhesion layer in some embodiments, at the interface of theNFT material and the cladding material layer can “dampen” the ability ofthat interface to support surface plasmons, which can result in weakerelectric field emission from the NFT. Such materials may also haverelatively favorable k values. In some embodiments, materials that aremore highly detrimental from an optical standpoint can be utilized atrelatively smaller thicknesses, for example.

Materials of the adhesion layer can also be designed to interact withthe material of the NFT itself, for example a dopant in a primarymaterial of the NFT, the primary material of the NFT, or a combinationthereof. In some embodiments, a NFT is formed by the application ofheat, e.g., annealing, to add one or more elements into a NFT made of aprimary material. After annealing, the NFT material and one or moresecondary elements mix together and the secondary element is uniformlydoped in the material of the NFT (e.g., an Au film or layer). The heattreatment can be done at any of the following stages: 1) afterdeposition of the NFT and secondary element, before peg formation; 2)after the peg is formed, but before the adhesion layer and NPS isdeposited; 3) after the top adhesion layer and NPS are deposited, butbefore a final air bearing surface (ABS) with a head overcoat is formed;or 4) after a final ABS with a head overcoat is formed. The heattreatment conditions can be chosen so that they are sufficient to drivethe desired atom redistribution, but not harsh enough to cause Au graingrowth and/or peg deformation. It should also be noted that thediffusion of the secondary atoms can react with the material of theadhesion layer to strengthen the interface and promote adhesion.

Methods of making devices including disclosed adhesion layers can varydepending on the location of the adhesion layer. In embodiments whereone or more adhesion layers are being utilized on the first surface 307,the third surface 308, the fourth surface 311, or any combinationthereof, the adhesion layer(s) can be deposited, then the NFT materialcan be deposited, followed by the cladding or dielectric material. Theadhesion layer(s) then affects adhesion between the underlyingdielectric material (for example the cladding layers or dielectriclayers) and the NFT. In embodiments where an adhesion layer is utilizedon the second surface 309, the adhesion layer material can be depositedon the NFT material after it is deposited, for example in a trench(either lined with a disclosed adhesion layer material or not). Theadhesion layer on the second surface 309 then affects adhesion betweenthe NFT material and the overlying dielectric material (for example thetop cladding layer). In some embodiments, an adhesion layer material canbe deposited on a NFT material layer. This structure can then be trimmedin order to form a peg (from the NFT material layer) with an adhesionlayer on the first surface 307 of the peg. Next, an adhesion layer canbe formed on the third surface 308, the fourth surface 311 and thesecond surface 309. Excess adhesion layer material can then optionallybe removed from the structure.

FIGS. 5A through 5D depict an illustrative process sequence to form adevice that includes disclosed adhesion layer. The device to be formedusing this illustrative process includes adhesion layers on the bottom,the sides and the top of the peg and a portion of the disc. With respectto FIGS. 3A and 3B, the adhesion layer formed using such an illustrativeprocess would be on the first surface 307, the second surface 309, thethird surface 308 and the fourth surface 311 of the peg 305, as well ason the surface of the disc 310 facing the peg 305 (see FIG. 3A).

The illustrative process demonstrated in FIGS. 5A to 5D includes a onepiece NFT, which implies that the disc and peg of the NFT are formedtogether in one ion mill process. FIG. 5A shows the core 510, thecore/NFT space (CNS) 513 that is made of a cladding material, a firstsurface (or bottom) adhesion layer 515, and the already formed NFT 520.The NFT 520 can be formed, for example, with photolithography techniquesincluding patterning photoresist and amorphous carbon hardmask forexample. Once the photolithography techniques have been used to form thegeneral structure, the NFT can be milled with a bit of overmill into theCNS to form the CNS 513 and NFT 520 seen in FIG. 5A. The amorphouscarbon hard mask can be ashed away, for example in an O₂ plasma asher.FIG. 5B shows the structure after a non-optically sensitive material andphotoresist material have been applied. The non-optically sensitivematerial is utilized to create an undercut during lithography. In someembodiments, the non-optically sensitive layer 525 can includepolymethylglutarimide (PMGI) for example. The non-optically sensitivelayer 525 and the photoresist layer 530 after being patterned to providean undercut protects a majority of the disc area leaving only the pegarea and a portion of the disc near the peg exposed. The structure inFIG. 5B therefore includes all of the previous components as well as apatterned photoresist layer 530 and an undercut non-optically sensitivelayer 525. The first patterned photoresist 525 and the patternedphotoresist 530 leave only the three surfaces (top and sides) of the pegand a portion of the disc facing the peg exposed. FIG. 5C shows thestructure after an adhesion layer 535 has been deposited on the exposedsurfaces of the peg and disc, and the first patterned photoresist 525and the second patterned photoresist 530 have been removed with aliftoff process for example. FIG. 5D shows a cross section of thestructure. The structure includes the core 510, the CNS 513, the bottomadhesion layer 515, the NFT 520 including the peg 521 and the disc 522,and the adhesion layer 535. As seen in FIG. 5D (and FIG. 5C), theadhesion layer 535 is disposed on at least a portion of the disc 522.Although not seen in FIG. 5D (but visible in FIG. 5C), the adhesionlayer 535 is on both the top and the sides of the peg 521. It should benoted that the process flow depicted in FIGS. 5A to 5D is only anillustrative example of a process flow that could be utilized to form anadhesion layer on the bottom, top and sides of a peg as well as aportion of a disc.

The illustrative process demonstrated in FIGS. 6A to 6D includes a twopiece NFT, which implies that the disc and peg of the NFT are formed indifferent process steps. FIG. 6A shows the core 610, the core/NFT space(CNS) 613 that is made of a cladding material, a first surface (orbottom) adhesion layer 615, and a rod 623 that eventually becomes partof the NFT. The rod can be formed by depositing a layer of plasmonicmaterial (e.g., gold), patterning the layer with amorphous carbonhardmask, for example, and then milling. After the milling step, theamorphous carbon hardmask can be ashed away. FIG. 6B shows the structureafter the disc 622 and the heat sink 624 are formed over the rod toprovide the peg 621 using a liftoff process. FIG. 6C shows the structureafter an adhesion layer 635 is formed over the peg and at least aportion of the disc and heatsink of the NFT 620 (using the same liftoffprocess for example). FIG. 6D shows a cross section that includes thecore 610, the CNS 613, the bottom adhesion layer 615, the peg 620 andthe adhesion layer 635. Although not seen in FIG. 6D (but visible inFIG. 6C), the adhesion layer 635 is on both the top and the sides of thepeg. It should be noted that the process flow depicted in FIGS. 6A to 6Dis only an illustrative example of a process flow that could be utilizedto form an adhesion layer on the bottom, top and sides of a peg as wellas a portion of a disc.

In process flows such as those depicted via FIGS. 5A to 5D and 6A to 6D,the materials utilized in the adhesion layers (both bottom andtop/sides) may optionally be chosen in such a way that after annealingsecondary atoms in the main NFT material can diffuse into the NFT/CNSinterfaces and react with adhesive material that is covering all theNFT/CNS interfaces without forming intermetallic compounds thatdestabilize the interface. The material choices of the secondary atomsin the NFT and the adhesion layer may be made by considering at leastsome of the following: 1) the secondary atom can have a positive heat ofmixing with the main NFT material, whereas the adhesion layer materialcan have a slightly negative heat of mixing with the NFT material; 2)the secondary atom can react with the adhesion layer material to form anamorphous layer that has relatively high affinity to oxygen and the NFTmaterial respectively; 3) the secondary atoms and the adhesion layeratoms may be chosen to restrict the NFT material (e.g., Au) grain growthduring operation and both the secondary atom and the adhesion layermaterial may enable densification of the main NFT material; 4) thesecondary atoms and the adhesion layer atoms may act as vacancy traps toreduce the peg recession; or some combination thereof. The adhesionlayer material and NPS may, in some embodiments be deposited in-situ forimproved adhesion integrity.

Some illustrative embodiments do not include adhesive materials beyondthe sides of the peg (as compared with the extent of the adhesion layer535 in FIG. 5C and adhesion layer 635 in FIG. 6C). Such embodiments mayreduce the thermal and optical penalty of the adhesion layer material.The process flows in FIGS. 7A to 7G and 8A to 8F show process flows toobtain such an adhesion layer with a two piece NFT (FIGS. 7A to 7G) anda one piece NFT (FIGS. 8A to 8F).

The illustrative process demonstrated in FIGS. 7A to 7D includes a onepiece NFT, which implies that the disc and peg of the NFT are formedtogether in one ion mill process. In this illustrative process, a layerof adhesive layer material is deposited, then a layer of NFT material(e.g., gold) is deposited, then a second layer of adhesive material(either the same or different than the first) is deposited, and finallya capping layer is deposited (this process forms a non-patterned stackof adhesive layer material/NFT material/adhesive layer material/cappinglayer material on a structure that already included a core/CNS claddinglayer structure). The capping layer can be any material that can protectthe top adhesion layer material from being oxidized in air or duringsubsequent patterning steps. An illustrative material for the cappinglayer includes, for example AlO. This layered structure is subjected toion milling via an amorphous carbon hardmask, for example, to form aNFT. This structure is shown in FIG. 7A and includes the core 710, thecore/NFT space (CNS) 713 that is made of a cladding material, a firstsurface (or bottom) adhesion layer 715, NFT 720 and second (or top)adhesion layer 735, capping layer 740 and hardmask 745. As seen in FIG.7B, the next step includes formation of an additional layer of adhesionmaterial 750 and second capping layer 755 on top of the hardmask 745 sothat the sides of the peg and disc are covered by adhesion layermaterial (the additional layer of adhesion material 750) and theadhesion layer 750 does not get damaged during subsequent processing(second capping layer 755).

The next step includes top down vertical ion milling to remove theadhesion layer from the field. Upon completion of this step, thehardmask 745 (e.g., amorphous carbon) will be exposed, the structureafter completion of this step is seen in FIG. 7C. Next, a cladding layere.g., AlO, is deposited in the entirety of the field to backfill thearea around the structure, this structure is seen in FIG. 7D, with thecladding layer 760 indicated therein. Next, a polishing step, e.g.chemical mechanical polishing (CMP) is undertaken that is configured tostop at the hardmask 745 layer. Amorphous carbon is a useful materialfor the hardmask 745 because it is a good CMP stop material, which willprotect the top adhesion material layer from being polished away. Thisstructure is depicted in FIG. 7E, with the backfill 761 and the hardmask745 indicated therein. After that, the hardmask 745 is removed. Ininstances where the hardmask 745 was amorphous carbon, it can be removedby ashing, for example by ashing with H₂ plasma, which can avoidoxidizing the adhesion layer. The structure after this step is seen inFIG. 7F, with the adhesion layer formed by the additional layer ofadhesion material 750 as indicated, the top adhesion layer 735, thesecond capping layer 750 and the capping layer 740. FIG. 7G shows across section. The structure includes the core 710, the core/NFT space(CNS) 713, a first surface (or bottom) adhesion layer 715, NFT 720 andsecond (or top) adhesion layer 735, capping layer 740, which canultimately form part of the top cladding or NPS space (NPS), the backadhesion layer 750, and back cladding 755.

The illustrative process demonstrated in FIGS. 8A to 8F includes a twopiece NFT, which implies that the disc and peg of the NFT are formed indifferent process steps. FIG. 8A shows the core 810, the CNS 813 that ismade of a cladding material, a first surface (or bottom) adhesion layer815, a rod 823 that eventually becomes part of the NFT, a top adhesionlayer 835 thereon, and a capping layer 840. The rod can be formed bydepositing a layer of plasmonic material (e.g., gold), patterning thelayer with amorphous carbon hardmask, for example, and then milling.After the milling step, the amorphous carbon hardmask can be ashed away.The capping layer can be any material that can protect the top adhesionlayer material from being oxidized in air or during subsequentpatterning steps. An illustrative material for the capping layerincludes, for example AlO. FIG. 8B shows the structure after the nextstep, which includes formation of an additional layer of adhesionmaterial 845 and second capping layer 850 on top of the capping layer840 so that the sides of the rod 826 are covered by adhesion layermaterial (the additional layer of adhesion material 845) and theadhesion layer 845 does not get damaged during subsequent processing(second capping layer 850). Next, the adhesion layer material in thefield is removed with vertical ion milling to give the structure seen inFIG. 8C that includes the side adhesion layer 846 and remaining cappinglayer 851. The next step prepares the structure for formation of thedisc and heat sink over the rod 823. This includes formation ofpatterned photoresist 855, which is shown in FIG. 8D. As seen in FIG.8D, the adhesion layers 835 and 846 and the capping layer 851 around thepeg inside the photo opening are milled away to expose the material ofthe rod. Then, finally the disc and heat sink are formed using a liftoffprocess and the patterned photoresist 855 seen in FIG. 8D is removed.This structure, including the peg 821 with adhesion layer 847 andpartial capping layer 852 thereon, and the disc and heat sink 822 isseen in FIG. 8E. FIG. 8F shows the cross section that includes the core810, the CNS 813, the lower adhesion layer 815, the peg 821, the discand heat sink 822, the top adhesion layer 835 and the capping layer 860,which can ultimately form part of the top cladding or NPS space (NPS).

Referring back to FIGS. 3A and 3B, an adhesion layer can also beutilized on the air bearing surface 306 of the peg 305. Inclusion of anadhesion layer on the air bearing surface 306 can be in combination withan adhesion layer on any other surface(s) of the peg, and can beaccomplished in combination with any disclosed processes or methodsdisclosed herein. In some embodiments, the deposition may be doneselectively to cover the NFT region only in order to protect themagnetic pole and/or reader stack, etc, through various processes,including for example photoresist patterning at the ABS, selective areaCVD or ALD deposition, Ion beam deposition (IBD), sputtering,electrodeposition, or any combination thereof. In some embodiments, aseed layer can also be included. The optional seed layer can include thesame or different material as the adhesion layer. In embodiments wherethe NFT includes a primary and a second material, the primary andsecondary material may mix together with the adhesion layer. As such,the adhesion layer may uniformly wrap the NFT from all sides of the peg,(e.g., the top, bottom, sides and the front of the peg).

Illustrative processes for forming disclosed adhesion layers can includefor example, deposition methods such as chemical vapor deposition (CVD),physical vapor deposition (PVD), atomic layer deposition (ALD), plating(e.g., electroplating), sputtering methods, cathodic arc depositionmethods, ion implantation method and evaporative methods. Conformalityon the side walls of the peg may also be advantageous, so materials andprocesses that can produce high conformality may be advantageous.Various deposition techniques can be used to achieve in-situ andconformal sidewall films such as sputtering or 2PCM or IBD or CVD or ALDor evaporation or electro-deposition or area-selective CVD orarea-selective ALD techniques.

Processes to form the adhesion layer could be easily integrated into theoverall manufacturing process of the device. Overall, the use ofdisclosed adhesion layers would decrease or eliminate yield loss due todelamination of the NFT and contribute to increased NFT lifetime duringthe operation of the magnetic device with very little effect on currentformation processes for the device.

All scientific and technical terms used herein have meanings commonlyused in the art unless otherwise specified. The definitions providedherein are to facilitate understanding of certain terms used frequentlyherein and are not meant to limit the scope of the present disclosure.

As used in this specification and the appended claims, “top” and“bottom” (or other terms like “upper” and “lower”) are utilized strictlyfor relative descriptions and do not imply any overall orientation ofthe article in which the described element is located.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise.

As used in this specification and the appended claims, the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise. The term “and/or” means one or all of thelisted elements or a combination of any two or more of the listedelements.

As used herein, “have”, “having”, “include”, “including”, “comprise”,“comprising” or the like are used in their open ended sense, andgenerally mean “including, but not limited to”. It will be understoodthat “consisting essentially of”, “consisting of”, and the like aresubsumed in “comprising” and the like. For example, a conductive tracethat “comprises” silver may be a conductive trace that “consists of”silver or that “consists essentially of” silver.

As used herein, “consisting essentially of,” as it relates to acomposition, apparatus, system, method or the like, means that thecomponents of the composition, apparatus, system, method or the like arelimited to the enumerated components and any other components that donot materially affect the basic and novel characteristic(s) of thecomposition, apparatus, system, method or the like.

The words “preferred” and “preferably” refer to embodiments that mayafford certain benefits, under certain circumstances. However, otherembodiments may also be preferred, under the same or othercircumstances. Furthermore, the recitation of one or more preferredembodiments does not imply that other embodiments are not useful, and isnot intended to exclude other embodiments from the scope of thedisclosure, including the claims.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc. or 10 or less includes 10, 9.4, 7.6, 5, 4.3,2.9, 1.62, 0.3, etc.). Where a range of values is “up to” a particularvalue, that value is included within the range.

Use of “first,” “second,” etc. in the description above and the claimsthat follow is not intended to necessarily indicate that the enumeratednumber of objects are present. For example, a “second” substrate ismerely intended to differentiate from another infusion device (such as a“first” substrate). Use of “first,” “second,” etc. in the descriptionabove and the claims that follow is also not necessarily intended toindicate that one comes earlier in time than the other.

Thus, embodiments of devices including a near field transducer (NFT) andat least one associated adhesion layer are disclosed. Theimplementations described above and other implementations are within thescope of the following claims. One skilled in the art will appreciatethat the present disclosure can be practiced with embodiments other thanthose disclosed. The disclosed embodiments are presented for purposes ofillustration and not limitation.

What is claimed is:
 1. A device comprising: a near field transducer(NFT), the NFT having a disc and a peg, and the peg having five surfacesthereof; and at least one adhesion layer positioned on at least one ofthe five surfaces of the peg, the adhesion layer comprising one or moreof the following: chromium (Cr), tantalum (Ta), iridium (Ir), zirconium(Zr), yttrium (Y), scandium (Sc), cobalt (Co), silicon (Si), nickel(Ni), molybdenum (Mo), niobium (Nb), palladium (Pd), titanium (Ti),rhenium (Re), osmium (Os), platinum (Pt), aluminum (Al), ruthenium (Ru),rhodium (Rh), vanadium (V), germanium (Ge), tin (Sn), magnesium (Mg),iron (Fe), copper (Cu), tungsten (W), hafnium (Hf), carbon (C), boron(B), holmium (Ho), antimony (Sb), gallium (Ga), manganese (Mn), silver(Ag), indium (In), bismuth (Bi), zinc (Zn), ytterbium (Yb), combinationsthereof.
 2. The device according to claim 1, wherein the NFT comprisesgold or an alloy thereof.
 3. The device according to claim 1, whereinthe at least one adhesion layer is located on a surface of the peg thatis along an axis having a core of a waveguide and a write pole.
 4. Thedevice according to claim 3, wherein the at least one adhesion layer islocated adjacent the core of the waveguide.
 5. The device according toclaim 3 further comprising at least one additional adhesion layerlocated on a surface of the peg that is perpendicular to the axis havingthe core and the write pole.
 6. The device according to claim 1, whereinall surfaces of the peg except the air bearing surface have an adhesionlayer thereon.
 7. The device according to claim 1, wherein all fivesurfaces of the peg have an adhesion layer thereon.
 8. The deviceaccording to claim 1, wherein the at least one adhesion layer has athickness from about 1 to 60 Å.
 9. A device comprising: an energysource; a near field transducer (NFT) configured to receive energy fromthe energy source, the NFT having a disc and a peg, and the peg havingfive surfaces thereof; and at least one adhesion layer positioned on atleast one of the five surfaces of the peg, the adhesion layer having athickness from about 10 Å to about 35 Å, and the adhesion layercomprising one or more of the following: boron (B), aluminum (Al),indium (In), or combinations thereof.
 10. The device according to claim9, wherein the at least one adhesion layer has a thickness from about 10Å to about 30 Å.
 11. The device according to claim 9, wherein the atleast one adhesion layer has a thickness from about 2 Å to about 30 Å.12. The device according to claim 9, wherein the NFT comprises gold oran alloy thereof.
 13. The device according to claim 9, wherein the NFTcomprises silver (Ag) or an alloy thereof.
 14. The device according toclaim 9, wherein the NFT comprises copper (Cu) or alloys thereof. 15.The device according to claim 9, wherein the energy source comprises alaser.
 16. The device according to claim 9 further comprising awaveguide, the waveguide configured to receive the energy from theenergy source and couple it into the NFT.
 17. The device according toclaim 16, wherein the at least one adhesion layer is located on asurface of the peg that is along an axis having the core of thewaveguide.
 18. The device according to claim 17, wherein the at leastone adhesion layer is located adjacent the core of the waveguide.
 19. Amethod comprising: forming a structure, the structure comprising: abottom adhesion layer; a peg and disc structure on the bottom adhesionlayer, the peg and disc structure having both top surfaces and sidesurfaces; a second adhesion layer on the top and side surfaces of thepeg and disc structure; a capping layer on the second adhesion layer;and an amorphous carbon layer on the capping layer; and removing atleast a portion of the second adhesion layer via vertical ion millingand chemical mechanical polishing wherein the amorphous carbon layerfunctions as a stop layer for the second adhesion layer.